These 196 confirmed cases are among the total of 357 reports that CDC received of patients under investigation.

We continue to get regular updates from the CDC about AFM.

Unfortunately, we aren’t getting the real answer we were looking for – how to stop the outbreak.

Acute Flaccid Myelitis Update

Since the last update, we have learned that:

the case count is up to 196 confirmed cases (up from 193 last week)

an additional 161 cases are under investigation (up from 156 last week)

cases have been reported in 39 states (the same as last week)

That means that we have clearly exceeded the last record of 149 cases in 2016.

There are also 47 confirmed cases (up 9) and 28 cases under investigation in Canada this year.

In other news:

the CSTE will be issuing issued a new statement on AFM reporting reaffirming that they “are confident state and local health departments are working closely with doctors to ensure suspected cases are reported.”

Like this:

Although you may just now be hearing about acute flaccid myelitis, it is important to understand that it isn’t new.

The rise in AFM cases began in 2014 and seem to occur every other year.

It wasn’t even new when we started to see an increased number of cases a few years ago.

What is new, is that we are seeing an increased number of cases.

Acute Flaccid Myelitis Timeline

AFM refers to acute (sudden onset) flaccid (droopy or loose muscles) myelitis (inflammation of the spinal cord) and it is a subtype of acute flaccid paralysis.

If that explanation doesn’t really help you, it might help to understand that paralytic polio, like AFM, is another subtype of acute flaccid paralysis.

“In August 2012, the California Department of Public Health (CDPH) was contacted by a San Francisco Bay area clinician who requested poliovirus testing for an unvaccinated man aged 29 years with acute flaccid paralysis (AFP) associated with anterior myelitis (i.e., evidence of inflammation of the spinal cord involving the grey matter including anterior horn cell bodies) and no history of international travel during the month before symptom onset. Within 2 weeks, CDPH had received reports of two additional cases of AFP with anterior myelitis of unknown etiology.”

Unfortunately, they didn’t figure out what was causing the paralysis in these three patients, despite extensive testing and more cases followed.

“To identify other cases of AFP with anterior myelitis and elucidate possible common etiologies, CDPH posted alerts in official communications for California local health departments during December 2012, July 2013, and February 2014.”

Among 23 cases, California health officials found that the median age of the patients was 10 years old, only two tested positive for EV-D68, although most did have a recent “an upper respiratory or gastrointestinal prodrome.”

“Acute flaccid paralysis (AFP) with anterior myelitis is not a reportable condition, and baseline rates of disease are unknown but are likely quite low. Data from 1992–1998 on children aged <15 years in California indicated an incidence of 1.4 AFP cases per 100,000 children per year and did not identify a single case of AFP with anterior myelitis.”

California wasn’t the only state with cases.

In 2014, there were at least 12 cases in Colorado and 11 in Utah.

“In response to the CDPH and CHCO reports, the CDC established a case definition for enhanced nationwide surveillance of AFM, which included individuals less than 21 years of age with acute flaccid limb weakness and MRI involvement of predominantly the gray matter of the spinal cord without identified etiology presenting after August 1, 2014.”

All together though, in 2014, once the CDC began actively investigating cases, at least 120 cases were discovered in 34 states. The cases were associated with a large outbreak of EV-D68-associated respiratory illness, although they weren’t able to conclusively link those respiratory illnesses to the AFM cases.

Is there any evidence that there were a lot of cases before 2012?

Or that the CDC has dropped the ball and hasn’t been doing enough to investigate cases?

CDC activities include… using multiple research methods to further explore the potential association of AFM with possible causes as well as risk factors for AFM. This includes collaborating with experts to review MRI scans of people from the past 10 years to determine how many AFM cases occurred before 2014, updating treatment and management protocols, and engaging with several academic centers to conduct active surveillance simultaneously for both AFM and respiratory viruses.

CDC on the AFM Investigation

And if the first cases in California and Colorado triggered so much attention, isn’t it likely that any cases anywhere else would have done the same thing?

That makes it very unlikely that many cases were missed in earlier years.

EV-D68 first identified as a cause of respiratory tract infections – 1962

the first reports that EV-D68 could cause severe, even fatal respiratory disease – 2008

first AFM cases are discovered in California – August 2012

the Colorado Department of Public Health and Environment notifies the CDC about a cluster of AFM cases at Children’s Hospital Colorado and a joint investigation begins between the CDPH, CDC, and the physicians caring for the patients – September 2014

the CDC issues a health advisory on Acute Neurologic Illness with Focal Limb Weakness of Unknown Etiology in Children and calls on local and state health departments to report patients to the CDC – September 2014

the CDC conducts a conference call on Neurologic Illness with Limb Weakness in Children, so that clinicians could learn about the latest situation, surveillance, and CDC clinical guidance for AFM testing, patient evaluation and case reporting – October 2014

CDC Telebriefing on Acute Flaccid Myelitis in the US with Dr. Nancy Messonnier, director of CDC’s National Center for Immunization and Respiratory Diseases – August 2018

158 AFM cases confirmed in 36 states among 311 reported cases that are being investigated – 2018

The other issue that concerns many parents is why a definitive cause hasn’t yet been identified. And why don’t we have treatments or a cure yet?

“To date, no pathogen (germ) has been consistently detected in the patients’ spinal fluid; a pathogen detected in the spinal fluid would be good evidence to indicate the cause of AFM since this condition affects the spinal cord.”

CDC on AFM Investigation

Although enteroviruses can be difficult to detect in spinal fluid, it is important to keep in mind that isn’t the only thing that is keeping experts from declaring the investigation over and naming a cause, such as EV-D68.

Eyal Leshem on Notes from the Field: Acute Flaccid Myelitis Among Persons Aged ≤21 Years — United States, August 1–November 13, 2014

Another big issue is that EV-D68 has not been detected in every, or even most AMF patients, and many others have been found to have other enteroviral infections, including EV-A71.

Could it be a coincidence that investigators are finding these enteroviruses simply because it is the season for them to appear? That would mean something else is causing these kids to have AFM.

“During September–November 2016, 10 confirmed cases of AFM were reported in Washington. No common etiology or source of exposure was identified. Enterovirus-A71 was detected in one patient and EV-D68 in two patients, one of whom also tested positive for adenovirus.”

While the focus is on EV-D68 as a cause and everyone wants an answer, no one wants the CDC or other investigators to be wrong.

That doesn’t mean that they should be overly cautious and waste time or resources once an answer is evident, but just that they should follow sound epidemiological principles, get the right answer, and help stop kids from getting AFM.

What’s Next for AFM?

There are still a lot of unknowns about AFM, but this is likely what we can expect in the coming months:

the CDC will continue to investigate all unconfirmed cases that have occurred this year, which can take about four weeks after a case is reported and all necessary information is sent in. Keep in mind that since we don’t know if the CDC has already received all of the information on the cases they are investigating, we don’t know when they will finish investigating any pending cases.

local or state health departments will likely reach out to treating physicians to get followup about AFM patients about two months after they developed limb weakness and then report this short-term follow-up data to the CDC. In general, the CDC does not seem to contact patients directly.

From the current investigation, information from outbreaks and cases over the previous years, and cases in other countries, we will hopefully get the answers we need soon to prevent and treat AFM.

The AFM Surveillance Team will participate in a COCA Call in mid-November.

Maybe some of those answers will come during a Clinician Outreach and Communication Activity (COCA) Call on November 13, when members from the CDC Acute Flaccid Myelitis Surveillance Team discuss the “activities the CDC is conducting as part of its investigation into AFM.”

The fact that the CDC has an Acute Flaccid Myelitis Surveillance Team will be news and is hopefully reassuring to some folks…

This is also probably a good time to remind folks that funding for public health has been declining in recent years, even as we expect our public health officials to respond to more things and react more quickly to keep us all safe and healthy. Let’s make sure we fund our public health programs, including the CDC and NIH, so that they have all of the resources they need to address all of today’s public health challenges.

Many people were surprised by a comment by Dr. Robert Redfield, the director of the Centers for Disease Control and Prevention, in an interview for “CBS This Morning,” during which he said that acute flaccid myelitis:

“doesn’t appear to be transmissible from human to human.”

Wait, then how do kids get it?

Is Acute Flaccid Myelitis Contagious?

Since we don’t actually know what causes AFM, it is certainly possible, although rather unlikely, that it is caused by something that is not communicable.

But remember, the leading theory is that AFM is caused by an enteroviral infection, either EV-D68 and EV-A71, as most kids develop symptoms shortly after they had viral symptoms, and these two viruses are most commonly identified.

And you are typically contagious when you are sick with an enteroviral infection.

So how can the CDC Director say that AFM “doesn’t appear to be transmissible from human to human?”

It is because even if the virus that causes AFM is communicable, you can’t actually catch AFM from someone.

While the polio virus itself is communicable, paralytic polio isn’t. You can’t catch paralytic polio. Instead, you can catch polio, and then you have the small chance that it develops into paralytic polio.

It may not sound like a big difference, but it is.

Just consider what might happen if AFM itself was contagious, and if most of the kids who were exposed to someone with AFM developed AFM themselves…

We would likely see a lot more cases of AFM, especially in clusters in homes, daycare centers, and schools.

Instead, most cases seem to be isolated.

AFM Clusters

But aren’t there reports of clusters of AFM?

“In September 2016, an acute care hospital in Arizona notified the Maricopa County Department of Public Health (MCDPH) of a suspected case of AFM and subsequent cluster of 11 children who were evaluated with similar neurologic deficits; differential diagnoses included transverse myelitis and AFM.”

Notes from the Field: Cluster of Acute Flaccid Myelitis in Five Pediatric Patients — Maricopa County, Arizona, 2016

Yes, kind of.

But they aren’t clusters of epidemiological linked cases.

In Arizona, for example, only four of the 11 children were confirmed to have AFM and “no epidemiologic links were detected among the four patients.”

“In October 2016, Seattle Children’s Hospital notified the Washington State Department of Health (DOH) and CDC of a cluster of acute onset of limb weakness in children aged ≤14 years.”

Similarly, at Seattle Children’s Hospital, the ten cases in their “cluster” had nothing in common, except for having prodromal respiratory or gastrointestinal symptoms about seven days before developing AFM symptoms.

It is likely that you see “clusters” at some hospitals simply because they are referral hospitals for a large region.

But even if we don’t know why some kids with these viral infections develop paralysis and other don’t, if they are the cause, then you wouldn’t develop AFM if you never actually had the virus.

“While we don’t know if it is effective in preventing AFM, washing your hands often with soap and water is one of the best ways to avoid getting sick and spreading germs to other people.”

About Acute Flaccid Myelitis

So handwashing and avoiding others who are sick is still the best strategy to try and avoid getting AFM.

“Acute flaccid myelitis (AFM) is not nationally notifiable; CDC relies on clinician recognition and health department reporting of patients under investigation (PUIs) for AFM to learn more about AFM and what causes it.”

But could there be more cases?

The Case for Making AFM Reporting Mandatory

Although AFM isn’t yet a nationally notifiable disease, 120 other diseases are, from Anthrax and Botulism to Vibriosis and Zika virus disease.

The Nationally Notifiable Condition List depends on state laws for any mandate to report.

Who picks them?

The Council of State and Territorial Epidemiologists.

“Although AFP surveillance is commonly conducted in many countries currently still at risk for ongoing transmission of poliovirus, AFP is not a reportable condition in any U.S. state and routine surveillance and assessment for AFP is not performed. Therefore, understanding the baseline incidence and epidemiology of AFM and its public health impact in the United States is significantly limited.”

Revision to the Standardized Surveillance and Case Definition for Acute Flaccid Myelitis

Utilize standardized criteria for case identification and classification for acute flaccid myelitis (AFM) but do not add AFM to the Nationally Notifiable Condition List . If requested by CDC, jurisdictions (e.g. States and Territories) conducting surveillance according to these methods may submit case information to CDC.

Report cases as soon as possible and continue surveillance.

Share data to “measure the burden of acute flaccid myelitis (AFM).”

And the CDC has agreed.

“CDC concurs with this position statement. We look forward to continuing to work with our jurisdictional partners to address this important public health issue. This standardized case definition provides an opportunity to better define the spectrum of illness seen with AFM and to determine baseline rates of AFM in the United States. During review of the position statement, a few minor edits were identified as necessary for clarification, and we are working with the author to make these changes.”

What would be the difference if AFM was added to the Nationally Notifiable Condition List?

For one thing, because the list of reportable conditions varies from state to state, it would provide a uniform case surveillance and case definition.

But we already have that in the CSTE Position Statement on Acute Flaccid Myelitis.

The big issue is that there is no federal law that actually mandates reporting for the diseases on the list! Or even to report them to the CDC.

“Each state has laws requiring certain diseases be reported at the state level, but it is voluntary for states to provide information or notifications to CDC at the federal level.”

CDC on Data Collection and Reporting

It is up to state laws – in each and every state.

“The legal basis for disease reporting is found at the state level, where inconsistent laws may differ in terms of which conditions are reportable and their reporting process.”

Brian Labus on Differences In Disease Reporting: An Analysis Of State Reportable Conditions And Their Relationship To The Nationally Notifiable Conditions List

So even if the Council of State and Territorial Epidemiologists added AFM to the Nationally Notifiable Condition List, you would then need each state to pass a law adding AFM to their lists of notifiable diseases.

“Currently AFM is not a reportable condition in Texas.”

TxDSHS on Acute Flaccid Myelitis

How long would that take?

Zika is on the Nationally Notifiable Condition List, but guess what, like AFM, it isn’t on the reportable condition list in many states…

Utah, Washington and Colorado have already added AFM to their list of notifiable conditions. Has your state?

Want to get more cases of AFM reported to the CDC?

Let’s raise awareness about AFM and educate parents and health professionals to get all cases diagnosed, as they can then get reported to local and state health departments, who will then report them to the CDC.

Making AFM reporting mandatory might sound like a big deal, but will it really make any difference in getting kids diagnosed and treated?

“Ultimately, we would have to decide what the purpose of making something nationally notifiable is. We can investigate it just as well without that designation, and keeping things at the state level (for now) allows a lot more flexibility in how we define and investigate it. It might seem frustrating because it isn’t on the nationally-notifiable list, but that honestly doesn’t matter in terms of how we investigate things.”

Brian Labus, PhD, MPH

Cases still get investigated without being on the Nationally Notifiable Condition List.

Cases still get reported without being on the Nationally Notifiable Condition List.

And that’s good, because adding AFM to the Nationally Notifiable Condition List is not something that would happen overnight.

CP-CRE was added to the National Notifiable Condition List in 2018 at the 2017 CSTE annual meeting.

The CSTE would probably discuss it at their next meeting (next summer), and if approved, it would take effect at the beginning of the new year – January 2020. But then, then CDC has to get approval from the Office of Management and Budget (OMB) to actually get permission to start collecting the data on AFM for the Nationally Notifiable Condition List. All of that likely means that the earliest we would see “national” reporting for AFM would be sometime in 2022.

Does that mean we should jump on it now if it is going to take so long, or should we wait to figure out a definitive cause, and then put that on the Nationally Notifiable Condition List?

Whatever we do, remember that it still wouldn’t be mandated reporting unless each and every state actually passes a law mandating reporting of AFM cases to the CDC. Again, being on the Nationally Notifiable Condition List simply means that states are strongly encouraged to report their cases, as they do now. There are several diseases on the Nationally Notifiable Condition List that states never add to their own notifiable conditions list.

“It is voluntary that notifiable disease cases be reported to CDC by state and territorial jurisdictions (without direct personal identifiers) for nationwide aggregation and monitoring of disease data. Regular, frequent, timely information on individual cases is considered necessary to monitor disease trends, identify populations or geographic areas at high risk, formulate and assess prevention and control strategies, and formulate public health policies. The list of notifiable diseases varies over time and by state. The list of national notifiable diseases is reviewed and modified annually by the CSTE and CDC. Every national notifiable disease is not necessarily reportable in each state. In addition, not every state reportable condition is national notifiable.”

CDC on Data Collection and Reporting

Mostly, folks should understand that simply being on the Nationally Notifiable Condition List may not mean as much as they think it does.

“Although disease and condition reporting is mandated at the state, territory, and local levels by legislation or regulation, state and territory notification to CDC is voluntary. All U.S. state health departments, five territorial health departments, and two local health departments (New York City and District of Columbia) voluntarily notify CDC about national notifiable diseases and conditions that are reportable in their jurisdictions; the data in the case notifications that CDC receives are collected by staff working on reportable disease and condition surveillance systems in local, state, and territorial health departments.”

CDC on Data Collection and Reporting

And that epidemiologists at the local, state, and national level are working hard to identify all cases of AFM, which will hopefully help them figure out what is causing these cases, how to treat kids who are already affected, and how to prevent new cases.

They are identifying more and more cases of AFM even though few states have mandatory reporting, AFM isn’t on the Nationally Notifiable Condition List, and reporting of cases to the CDC is voluntary.

Most people are aware that there is a so-called “mystery illness” going around.

A “mystery illness” that is paralyzing some kids.

What’s so mysterious about it?

What is Acute Flaccid Myelitis?

Lots of things are mysterious about acute flaccid myelitis…

We don’t know exactly what causes it, who will get it, why they get it, or how to treat it, etc.

What do we know?

AFM is not new, although we are seeing more cases lately

AFM refers to acute (sudden onset) flaccid (droopy or loose muscles) myelitis (inflammation of the spinal cord) and it is a subtype of acute flaccid paralysis

most cases occur in children, with the ages of affected children ranging from 5 months to 20 years, although some adults have been affected

these children have a magnetic resonance image (MRI) showing a spinal cord lesion largely restricted to gray matter and spanning one or more vertebral segments

it is thought that AFM can be caused by viruses (polio, non-polio enteroviruses, West Nile virus, Japanese encephalitis virus, CMV, EBV, adenovirus, etc., environmental toxins, and genetic disorders, and although no common etiology has been found in these recent cases, most experts think that these cases are caused by a neuroinvasive infectious process, likely of viral etiology, including EV-D68 and EV-A71.

these cases of AFM are not thought to have a post-infectious immune-mediated etiology

cases are occurring sporadically – after 120 cases in 34 states in 2014, there were only 24 cases in 17 states in 2015, but then 149 cases in 39 states in 2016 and 33 cases in 16 states in 2017. And there have been at least 158 cases in 36 states in 2018, with another 153 cases under investigation.

outbreaks of EV-D68 and sporadic cases of AFM have also been seen in other countries recently, including Denmark, France, the Netherlands, Spain, Sweden and the United Kingdom (UK)

most cases occur in the late summer and early fall

most had symptoms of a preceding viral illness, including respiratory symptoms or diarrhea

While that’s a lot of good information, for parents wanting to protect their kids and avoid AFM, there is some key information missing. Same for those wanting to help treat their kids who have or have had AFM.

So although some folks don’t like that it is being called a “mystery illness,” there is still a lot of mystery to it.

You would first have to make a individual vaccines, before thinking about combining them, and you can’t just make any vaccine you want. If you could, we would have vaccines to protect us against RSV, malaria, HIV, and many other diseases.

Still, since EV-A71 also causes serious outbreaks of hand, foot, and mouth disease in some parts of the world, a vaccine has actually been in development for some time, and two are approved for use in China. That at least means making an EV-A71 vaccine is possible, although we would likely need to make our own.

Why did they make a vaccine for a virus that causes hand, foot, and mouth disease (HFMD)? Because unlike the HFMD that we are used to, which is typically caused by coxsackievirus A16 virus, another enterovirus, when caused by EV-A71, it can be deadly, as we have seen in outbreaks in Asia.

What about an EV-D68 vaccine?

While likely possible, since developing a new vaccine takes a lot of time, we want to be sure that is what is causing the outbreaks.

Do some kids not have either EV-D68 or EV-A71 because it just isn’t detected or because something else is causing them to have AFM? Possibly. One of the biggest issues that is troubling some experts though is that they have not detected these enteroviruses in the spinal cord fluid of many children, as you would expect if the viruses were causing the damage.

But even if these enteroviral infections are the cause, are there other risk factors that make some kids who get these enteroviral infections more predisposed to develop AFM, instead of more typical viral symptoms, like a cold or diarrhea?

And why are we seeing cases now? Did the virus, if that is the cause, just mutate into one that is more virulent?

Hopefully we get some more answers and a way to prevent, treat or cure AFM soon.

Until then, we can make sure we take steps to prevent the known causes of AFM, including polio (get vaccinated) and West Nile virus (use insect repellent), and wash hands properly to help avoid all other viral infections. You also want to get your flu vaccine! The flu can cause Guillain-Barré syndrome, which can also cause AFM.

“…is there any relationship between vaccination status and a developing acute flaccid myelitis? Meaning, are vaccines a risk factor? And the data so far says no, the overwhelming number of children who have gotten AFM have had no recent vaccination of any kind or vaccine exposure. These cases over these years have been happening before flu season and flu vaccination starts, which is one of the questions that comes up, and there hasn’t been any pattern to vaccine exposure of any kind in developing AFM. So far, we have not found a link between the two.”

What to Know About Acute Flaccid Myelitis

While it might be scary to think that there is a new condition out there that we don’t know everything about, parents should be reassured that experts are actively seeking the cause and a way to both prevent and treat AFM.